Add Serialization & Deserialization of Sink File Properties with CLI Commands

[Copilot]

This PR implements file sink telemetry configuration for Data API Builder, enabling users to send logs to a file sink through CLI commands and JSON configuration.

Changes Made

CLI Commands Added

The following new CLI configure options are now available:

• --runtime.telemetry.file.enabled - Enable/disable file sink telemetry (default: false)
• --runtime.telemetry.file.path - File path for telemetry logs (default: "/logs/dab-log.txt")
• --runtime.telemetry.file.rolling-interval - Rolling interval: hour, day, week (default: day)
• --runtime.telemetry.file.retained-file-count-limit - Number of retained files (default: 1, minimum: 1)
• --runtime.telemetry.file.file-size-limit-bytes - Max file size in bytes (default: 1048576, minimum: 1)

Usage Examples

# Enable file sink with default settings
dab configure --runtime.telemetry.file.enabled true

# Configure all file sink options
dab configure --runtime.telemetry.file.enabled true \
  --runtime.telemetry.file.path "/var/log/dab.log" \
  --runtime.telemetry.file.rolling-interval week \
  --runtime.telemetry.file.retained-file-count-limit 7 \
  --runtime.telemetry.file.file-size-limit-bytes 10485760

JSON Configuration Schema

The configuration now supports the following structure under runtime.telemetry:

{
  "runtime": {
    "telemetry": {
      "file": {
        "enabled": true,
        "path": "/logs/dab-log.txt",
        "rolling-interval": "day",
        "retained-file-count-limit": 7,
        "file-size-limit-bytes": 1048576
      }
    }
  }
}

Implementation Details

Object Model Changes:

• Added FileOptions record with proper JSON serialization
• Added RollingInterval enum supporting hour/day/week intervals
• Updated TelemetryOptions to include file sink configuration

JSON Schema Updates:

• Added complete file sink schema definition with constraints and defaults
• Proper enum validation for rolling intervals
• Minimum value constraints for numeric fields

Configuration & Validation:

• Full integration with existing dab configure command infrastructure
• Input validation for numeric constraints (minimum values)
• Support for configuring multiple options in a single command
• Comprehensive error handling and logging

Testing:

• Added 14 unit tests covering all configuration scenarios
• Tests for successful updates, validation failures, and multi-option configuration
• End-to-end validation from CLI to JSON serialization

Validation

All tests pass and the implementation follows existing patterns in the codebase for telemetry providers (similar to ApplicationInsights and OpenTelemetry implementations).

Fixes #2576.

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